Re: Altimeter Calibration Height

Steven P. McNicoll wrote:
"Matt Whiting" <whiting@xxxxxxxx> wrote in message
news:pjBQh.3553$Oc.184864@xxxxxxxxxxxxxxxxx
Right and the altitude indicated has little to do with the altitude of the
instrument.


Right. That's why changing the altitude of the instrument, as is done by
climbing or descending, has so little effect on the indicated altitude.



I can just as easily change the Kollsman setting and change the indicated altitude without changing the altitude of the instrument at all. Or I can wait for the ambient pressure to change and watch the indicated altitude change without moving the instrument. Thus the instrument doesn't indicate the altitude of itself, it indicates the pressure it is experiencing.

If the altimeter truly indicated the altitude of the instrument, then it would only change when the altitude of the instrument changed. Since that isn't the case, it follows logically that the altimeter isn't indicating its own altitude, but rather something else ... pressure.

You can write whatever on the dial you want to, that doesn't change what is being indicated. I could write 10 oranges, 20 oranges, 30 oranges, etc, around my speedometer, but that doesn't make my speedometer indicate oranges.


Matt
.

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